1. Field of the Invention
The invention concerns a process by which the administration of medication is rendered more effective. More specifically, the invention concerns a process, which makes it possible for the first time to substantially completely recover the entire "residual" volume of pharmaceutical supplied in a drug supply vial, and to administer the recovered medicament in precise amounts, avoiding wastage and saving costs.
2. Description of the Related Art
The cost of pharmaceuticals represents a significant portion of the overall cost of health care. It is not uncommon for some pharmaceuticals to cost $100.00 per cc. These pharmaceuticals are supplied to hospitals, pharmacies and clinics in vials sealed with elastomeric stoppers.
For administration to a patient, a requisite amount of pharmaceutical must be transferred from the vial to a hypodermic syringe. This usually involves (1) drawing a volume of air into the syringe barrel substantially equal to the desired volume of pharmaceutical, (2) introducing the needle tip through the elastomeric stopper and into the vial reservoir, (3) injecting the air into the vial, (4) gravitationally inverting the vial, making sure that pharmaceutical covers the tip of the needle, and (5) drawing a measured amount pharmaceutical from the vial into the chamber of the barrel. The medical practitioner must watch the syringe to make sure the desired volume of pharmaceutical is withdrawn, and simultaneously monitor the vial to make sure that the tip of the needle remains covered with medication. As the volume of pharmaceutical is depleted, the practitioner gradually moves the needle. The last portion of the pharmaceutical is often difficult to extract.
U.S. Pat. No. 5,776,124 (Wald), teaches that the needle tip conventionally projects 0.5 inches into the liquid contents of the vial, raising the danger of drawing air into the syringe, particularly if the vial is not filled with sufficient liquid. Wald further teaches the danger of damaging or bending the fragile needle. In response to these problems, Wald teaches a flexible adapter which is seated on the vial and serves as a guide for the syringe needle, thereby preventing bending and damage, and gauging the depth of penetration of the needle into the vial.
Syringe design has recently developed as an area in which it has been attempted to realize cost savings by minimizing drug wastage. Most prominently has been the development of the "no dead space" syringe, one example of which is disclosed in U.S. Pat. No. 5,902,269 (Jentzen). While fixed needle "no dead space" syringes were known, Jentzen provides a syringe which has both interchangeable needles and no dead space. For comparative purposes, an example is given for a conventional syringe in which, for a 1.00 milliliter injection, 0.08 milliliter (or 8% of the dosage) remains in the "hub"--the part of the needle which engages with the barrel "collar"--the conical tapered nozzle area of the barrel. As is apparent from this patent, this seemingly miniscule amount pharmaceutical represents an economically significant cost savings, particularly when considering the amount of saved pharmaceutical is multiplied by the number of injections per day in the United States.
The present inventor has discovered yet another area in which drug wastage could potentially be avoided and cost savings realized.
More specifically, the inventor noted the natural tendency of fluid pharmaceuticals to cling to the side-wall surfaces of the vial as the pharmaceutical is being withdrawn. After the entire contents of a vial are believed to have been withdrawn and the "empty" vial has been allowed to sit quietly for a period of hours or days, it can be seen that a small amount of residual pharmaceutical pools at the bottom of the vial. Where expensive pharmaceuticals are involved, several institutions have instituted procedures of collecting these "empty" vials, storing them, and after having collected a number of vials, withdrawing the residual pharmaceuticals.
Presently available is a 1 cc capacity insulin syringe that has a permanently attached 5/8 inch 25 gauge needle. The needle is of a length which permits subcutaneous injection, yet must be kept short enough to prevent that the injection becomes intramuscular instead of subcutaneous. Since such a short needle is not capable of reaching all the way from the stopper to the bottom of a vial, and since such a needle is rather thin and flimsy, an insulin syringe obviously can not be used in the collection process. Instead, a larger syringe (e.g., 3 or 5 cc), fitted with a correspondingly larger needle, is now being used in some institutions to withdraw and collect residual pharmaceuticals.
A problem with this practice is that, even if a sufficient amount of pharmaceutical is collected in a 3 or 5 cc syringe, the syringe can not be directly used for administering pharmaceuticals, since such a large syringe can not accurately dispense small dosages of pharmaceuticals. Thus, the collected pharmaceutical must be somehow transferred to a small volume (1 cc) insulin syringe which is marked in 0.1 cc gradients and can more accurately administer small amounts of pharmaceutical. This practice of transference is associated with wastage, since least two syringes (a collection syringe and an injection syringe) must be used to administer a dosage of pharmaceutical. Further, the practice is inconvenient, requiring manual dexterity and patience, and is time-consuming.
The inventor thus determined that there was a need for a more efficient and economical method for administering pharmaceuticals.